Compressed air circuit breaker



Feb. 29, 1944. L. R. LUDWIG ETAL 2934'2,8Gg

COMPRESSED AIR CIRCUIT BREAKER Filed March 51, 1942 5 Shee-tsSheeh l 5/ WITNESSES: INVENTOIlS 4605' 1511/53? l a /anvxb L b 2a Ker n a ames fi Z Cum 1717) Feb" 29, 1944.

L. R. LUDWEG ETAL. 2,342,809

COMPRESSED AIR CIRCUIT BREAKER Filed March 31, 1942 3 Sheets-Sheet 2 fig 2,

WITNESSES: INVENTOR5 ZzFDn/Fluaw/ .Bgajam/n Fflfln r" 2 Va Ono am as f4. Cum 1H9. 4/.

, r B\ p ATTORI EY Feb. 29, 1944. 1.. R. LUDWIG ETAL COMPRESSED AIR CIRCUIT BREAKER Filed March 31, 1942 3 Sheets-Sheet 3 e 7 5 6 Av 9 33 77 V ZZEEZ my 7 9 w H F1 w m 3 w i m WITNESSES:

Patented Feb. 29, 1944 2,342,809 COMPRESSED AIR CIRCUIT BREAKER Leon R. Ludwig, Forest Hills, and Benjamin P.

Baker and James M. Cumming,

Pa., assignors Manufacturing Turtle Creek,

to Westinghouse Electric a Company, East Pittsburgh, Pa.,

a corporation 01' Pennsylvania Application March 31, 1942, Serial No. 437,010

20 Claims.

The invention relates to circuit breakers and more particularly to fluid blast circuit breakers of the fluid pressure operated type.

An object of the invention is the provision of an improved porcelain-clad compressed gas operated circuit breaker having a porcelain enclosed movable disconnect contact member.

Another object of the invention is the provision of a porcelain-clad compressed gas operated circuit breaker having an interrupting element and a movable arcing contact member which after arc extinction moves out of the interrupter into a porcelain enclosed disconnect chamber to introduce a disconnecting gap in the circuit.

Another object of the invention is the provision of a circuit breaker as described in the preceding paragraph, wherein the disconnect chamber is formed by a. hollow supporting insulator which supports the interrupting element, and the pas sage or chamber of the insulator serves as a gas blast passage.

Another object of the invention is the provision of a compressed air circuit breaker pole unit having a single operating cylinder and piston for first drawing an arc in the interrupting element and then inserting a porcelain enclosed disconnecting gap in series with the interrupter.

Another object of the invention is the provision of a compressed air circuit breaker pole unit having a simple operating mechanism comprising a single unitary casting formed to provide an operating cylinder, and an air blast passage for the arc extinguishing blast.

Another object of the invention is the provision of a compressed air operated circuit breaker with an air control system including simple dump valve mechanism comprising a single valve member o erated by the opening and closing air to dump air from the cylinder in front of the moving operating piston to atmosphere to facilitate high speed closing-opening operation and high speed reclosing operation.

Another object of the invention is the provision of a circuit breaker having a dump valve as described in the preceding paragraph, wherein the single piston type valve element has different pressure reactive areas to cause an opening operation to take precedence over a closing operation in case of conflicting impulses.

Another object of the inv'ention is the provision of a compressed air circuit breaker that is simple, fast and reliable in operation and inexpensive to manufacture.

The novel features that are considered characteristic of the invention are set forth in parporting insulator 2|.

ticular in the appended claims. The invention itself, both as to structure and operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of several embodiments thereof when read in conjunction with the accompanying drawings, in which:

Figure 1 is a front elevational view, partly in section, of a three-pole circuit breaker embodying the features of the present invention;

Fig. 2 is a side elevational view, partly in section, of the circuit breaker;

Fig. 3 is a sectional view, on an enlarged scale, of one of the pole unit operating mechanisms and the dump valve thereof;

Fig. 4 is a bottom view of in Fig. 3; and

Fig. 5 is a sectional view showing a modification of the dump valve mechanism.

Referring to Figure l of the drawings, the three-pole circuit breaker has three circuit interrupting pole units 9 which are mounted in spaced relation on a structural supporting frame ii. The three-pole units are of identical construction and each unit comprises three hollow supporting insulators l3, l5 and ll secured to the frame in triangular spaced relation and rising vertically therefrom. Supported on the upper end of the insulators is a casing [9 for housing the contact operating mechanism more clearly shown in Fig. 3. The casing l9 supports a hollow insulator 2| which, in turn, supports a circuit interrupting element or are extinguishing structure 23. A hollow insulator 25 extends upwardly from the arc extinguishing structure 23 and has a metallic terminal cap 21 secured on its upper end, and this cap forms the upper terminal of the pole unit. A stationary contact member 29 extends downwardly from the terminal cap 21 into the arc extinguishing structure 23. A cooperating movable contact member 3| coac'ts with the sta tionary contact member 29 and extends downwardly through the arc extinguishing structure 23 and through the passage of the hollow sup- The lower end 01' the contact member 3| extends into the casing 19 and is connected to an operating piston of the operating means as shown in Fig. 3.

The movable contact member 3| functions as the arcing contact and also as a disconnecting contact member as will be described hereinafter. The contact member 3| is electrically connected by means of a resilient multiple finger contact assembly 33 (Fig. 3) and through the operating cylinder casting, which is of conducting mate the mechanism shown rial, to aterminal 35 which is secured to a. projection 38 (Fig. 3) on the lower end of the cylinder casting and projects outwardly from the casing l9. Y

Extinction of arcs drawn by the movable contact member 3| takes place in the chamber of the" arc extinguishing structure 23 and is accomplished by a blast of compressed gas, in this instance compressed air, directed through the passage of the hollow insulator 2| to the arc extinguishing structure 23 and the current arc. The arc extinguishing structure 23 is of the radial blast type generally similar to the structure disclosed in the copending application of L. R. Ludwig and B. P. Baker, Serial No. 373,856, filed January 9, 1941, U. S. Patent 2,313,159 issued March 9, 1943, and assigned to the assignee of the present invention. 7

The are extinguishing structure comprises a pair of metallic flanged end members 31 and 39, the lower member 39 being secured to the insulator 2| through which the contact member 3| extends and also through which gas may fiow from the passage of the hollow insulator. The upper flanged end member 31 supports the insulator 25 and has a central opening through which the stationary contact extends. Disposed between the members 31 and 39 are a plurality of baffie members 4|, 43 and 45 ofinsulating mate-' rial, each of which has a central opening therethrough. The upper baflle member 4| has a central recess adjoining the central opening thereof. This cooperates with an air flow director surrounding the end of the stationary contact to direct the blast of air radially to the are which plays through the central orifice in the baffle member 4|. The space between the flanged end member 31 and the upper baiiie member 5| is connected with the chamber formed by the lower flange member 39 by a plurality of tubular members 11 which also serve to space the baflie members apart. Compressed air can thus flow from the passage of the hollow insulator 2| through the tubular members 41 through the chamber provided between the upper flange member 31 and the baffie member 4|, where it is then directed radially inwardly toward the central orifice in the upper baffle member 4|, This fiow of compressed air radially inwardly with high velocity subjects the are playing within the central orifice to a strong de-ionizing influence as the stream of com-' pressed air is turned from its radially inward direction to a direction parallel with the arc as the discharge takes place through the central orifice. The direction of blast air fiow in passing through the orifice changes direction and fiows radially outwardly in the space between the upperbaffie member 4| and the central baffie member 43. The are is thus quickly extinguished in the arc extinguishing structure by the deionizing and extinguishing action of the air blast.

Fluid under pressure, in this instance compressed air, for extinguishing the arcs and also for'operating the contact members is stored in a common reservoir or tank 5| mounted within the frame Compressed air is stored and maintained at a predetermined pressure in the tank 5| by a suitable motor driven compressor unit (not shown).

Each movable contact 3| of the three-pole breaker is operated to open and closed circuit position by an individual compressed air operand provided with an opening.

ating mechanism comprising a double acting piston 53' (Fig. 3) movable vertically in a relatively long operating cylinder 55 which is formed in a metal casting 51, there being an individual cylinder casting 51 and compressed air operating piston 53 for each of the three movable contact members 3|. Each contact operating mechanism is mounted within its corresponding cas ing |9, and the three operating pistons 53 are adapted to be operated simultaneously to open or close the breaker by compressed air from the tank 5|, the flow of compressed air for opening and closing the three poles of the circuit breaker being controlled by a single opening valve mechanism 59 and a single closing valve mechanism 6| (Fig. 1).

Referring to Fig. 3, the cylinder casting 51 has-an air blast tube 63 formed integral therewith communicating at its lower end with the passage through the hollow insulator I3 and communicating at its upper end with the passage of the hollow supporting insulator 2|, this tube and the aforementioned passages through the insulators I3 and 2| forming a path for the blast of compressed air which is directed to the arc extinguishing structure during circuit opening operations.

A separate air blast valve, indicated generally at 61 (Figs. 1 and 2), is provided for each of the three pole units of the circuit breaker. Each blast valve 61 includes a housing, the lower end 7 of which is connected by a pipe 69 to the air reservoir tank 5|. The upper end of the blast valve housing is connected by a short section of pipe 1| to the passage of the hollow supporting insulator i3 of its corresponding pole unit. The valve element 13 (Fig. 1) within the blast valve housing is connected by means of a rock shaft 15 and a rocker arm 11 to a blast valve operatin piston 19 disposed in a blast valve operating cylinder 8|. The blast valve is biased to closed position by a spring 82 disposed in the valve operating cylinder 19, and is adapted to be operated to open position by compressed air from the pipe 69 upon opening of a pilot valve ccn trolled by an electromagnet or solenoid 83. Thethree blast valve controlling solenoids 83 are electrically connected in parallel and arranged to be operated simultaneously with the operation of the opening valve mechanism 59, so that the blast air is directed to the arcs during the opening operation of the breaker. The center pole blast, valve mechanism is preferably interlocked with the opening valve mechanism by means of an interlock 85 so as to prevent operation of the opening valve mechanism 59 in the event that the blast valves fail to operate.

In accordance with the present invention, the contact member 3| functions both as an arcin contact and as a disconnecting contact member for inserting a relatively long and safe gap in the circuit after extinction of the are upon each circuit operating operation. When the piston 53 is moved downwardly by compressed air to open the circuit breaker, it moves through a relatively long stroke. During the initial portion of this stroke an arc is drawn in the upper section of the arc extinguishing structure 23 and is quickly extinguished in the chamber of the arc extinguisher b the blast of compressed air directed to the arc. After arc extinction, the movable contact member 3| continues its downward movement and is moved out of the arc extinguishing structure 23 and a considerable distance down into the passage of the hollow supporting insu- 2,842,809 later II to the open position shown in Fig. 2,

.end thereof is secured in an opening provided in the operating piston 53. The operating piston is also provided with a substantially square babbitted opening (not shown), in alignment with the tubular contact member 3|, for engaging a centrally disposed twisted square rod 87 which is rotatably mounted in a bearing provided in the lower portion of the lower cylinder head 89 secured to the bottom of the casting 51. The twisted square rod extends throughout the entire length of the operating cylinder and the lower end thereof has a crank arm 9i secured thereto which is connected by means of a linkag 93, 95 and 97 (Fig. i) to a rod 59 (Fig. 3). The rod 99 is suitably connected to a conventional multipole auxiliary switch (not shown). The operating piston 53 and the tubular contact member 3! slide telescopically on the twisted square rod 8'! as the piston is moved upwardly and downwardly in the operating cylinder, and this movement. due to the square opening in the piston and the twisted construction of the rod, causes the rod 87 to be rotated upon movement of the piston. This rotary movement of the rod 8'! operates the auxiliary switch through the agency of the linkage 93, 95, 97 and 99.

In order to facilitate high speed closing-opening operation and high speed reclosing operation of the circuit breaker, the air in the cylinder ahead of the direction of movement of the piston must be exhausted to atmosphere so that it will not retard movement or reversal of the operating piston. in. accordance with the present in" vention, this is accomplished by means of a simple automatic valve device indicated generally at 103 (Fig. 3). The valve device I 03 comprises a housing formed in two separate sections I05 and I! which are secured to a flattened surface formed on the cylinder portion of the casting 51. A single unitary slide valve member 109 is disposed for vertical sliding movement in aligned vertical passages provided in the valve housing sections 105 and I01. An air passage III formed in the upper end of the operating cylinder casting leads to the upper end of the operating cylinder 55 and is connected by a short section of pipe H3 to a passage II provided in the valve housing section I05. An inlet port H1 and an atmosphere exhaust port I21 communicate. with the passage H5. The inlet port is connected by a pipe IIS and by the passag through the 1101-- low insulator IE to an opening air manifold pipe IZI (Fig. 1) common to the three pole units of the circuit breaker. The compressed air for producing simultaneous opening operation of the three movable contact members 3| is adapted to fiOW thIOUgh the opening air manifold I2I and through the three hollow insulators I5, pipes I I9 and inlet ports I I I to the upper ends of the three operating cylinders 55. The opening air manifold I 2I is connected by a pipe I23 to the single opening valve mechanism 59, and this valve ing sections ers ISI serve to limit mechanism 33 is. in turn, connected by a pipe I35 to the air reservoir tank 3|.

An air passage I 2! formed in the lower end of the cylinder casting 3'! communicates with the lower end of the operating cylinder 83 and is connected through a short section of pipe 13! to a passage I33 formed in the lower section IO'I of the automatic valve housing. The passage I 33 communicates with an inlet port 33 and also with an exhaust port I31 formed in the section it! of the valve housing.

The inlet port 135 is connected by a pipe I and by the passage through the supporting insulator I? to a closing air manifold pipe I38 (Fig. 1) common to the three pole units of the circuit breaker. The closing air manifold pipe i 38 is connected by a pipe I to the closing valve mechanism II and this valve mechanism is, in turn, connected by pipe I43 to the air reservoir tank The single slide valve member 409 is pneumatically operated by the opening and closing air, and functions to automatically control opening and closing of the inlet and exhaust ports for each end oi" the operating cylinder. The valve member I09 has a piston element 54? threadedly mounted on each end thereof, these piston elements being slidably mounted in the aligned vertical passages of the housing sections Hi5 and M1. The connecting rod portion of the valve member I05 extends between the valve housing sections iIiS and W1 and slides through a sleeve I 49 loosely disposed between the two housing sections Hi5 and H11. Washers I5! are interposed between each end of the sleeve H9 and the corresponding housing sections )5 and I01, the stem or connecting rod of the valve being slidable through the washers. The overall length of the sleeve I49 plus the washers lot is slightly less than the distance between the opposed portions of the valve hous- I and It'll so that the sleeve and washers are movable vertically a limited amount between the housing sections. A compression spring IE3 encircles the sleeve I49 and the opposite ends of the spring bear against the loosely mounted washers Hi. The sleeve I49 and washupward and downward of the valve member Hi9 and the spring I53 acts to absorb the kinetic energy of the valve member at the ends of its stroke.

When compressed air iiows through the pipe I 68 to open the circuit breaker, the pressured air acting on the upper piston element HIT of the automatic valve member M8 pushes the valve member downwardly to its lower position. When the automatic valve member I4! is downwardly to its lowermost position, the upper piston element 1 thereof opens the inlet port ii! to admit compressed air to the upper end of the operating cylinder, and closes the corresponding exhaust port I 27 of the upper end of the cylinder. At the same time the lower piston element I41 opens the exhaust port I3! of the lower end of the cylinder and closes'the inlet port N5 of the lower end of the cylinder. Opening of the exhaust port I31 connects the lower end of the operating cylinder to atmosphere through this port, so that air below the operating piston is exhausted to atmosphere and cannot retard opening movement of the circuit breaker.

Conversely, when compressed air flows through movement the pipe B6 to close the breaker, the pressure air acting on the lower piston element I41 of the automatic valve member I09 moves the valve member to its uppermost osition as shown in thus pushed.

Fig. 3. When the valve member I09 is moved to its uppermost position, the lower piston element I41 thereof opens the inlet port I35 to admit compressed air to the lower end of the operating cylinder, and closes the exhaust port I31 of the lower end of the cylinder. At the same time the upper piston element I41 of the automatic valve member opens the exhaust port I21 for the upper end of the cylinder and closes the inlet port 1 for the upper end of the cylinder. Opening of the exhaust port I21 causes air in the cylinder above the operating piston to be exhausted to atmosphere, so that it will not retard closing movement of the operating piston and breaker.

The opening valve mechanism 59 and the closing valve mechanism 6| are of the same construction as disclosed in the copending application of B. P. Baker and A. H. Bakken, Serial No. 375,968, filed January 25, 1941, U. S. Patent 2,282,153 issued May 5, 1942, and assigned to the assignee of the present invention, and only a brief de-. scription thereof will be given in this application as the details of construction of these control valve mechanisms are not necessary to an understanding of the present invention. Referring to Fig. l, the opening valve mechanism has a valve element I51 which is biased closed and which is caused to be opened by air pressure from the pipe I25 when the pilot valve of the mechanism is operated upon energization of a solenoid I59.,

Similarly, the closing valve mechanism 6| has a valve element I63 which is biased closed and which is caused to be opened by compressed air from the pipe I43 when the pilot valve of the mechanism is operated in response to energization of a solenoid I65 associated with the valve.

The solenoids 83 of the three blast valves 61 and the solenoid I59 of the opening valve mechanism 59 are adapted to be energized simultaneously upon opening operations of the circuit breaker, and the solenoid I65 of the closing valve mechanism may be energized either alone or s multaneously with the three blast valve solenoids 83 upon closing operation of the breaker.

The operation of the circuit breaker is briefly as follows. Opening operation of the circuit breaker is initiated by simultaneous energization of the blast valve controlling solenoids B3 and the solenoid I59 of the opening valve mechanism 59. Opening of the valve 59 causes compressed air to flow from the tank 5| through the opening air manifold I2I, through the three porcelain insulators I5, pipes I I9 and inlet ports I I1 to the upper ends of the three operating cylinders 55. The pressure of the closing air in the pipes I I9 pushes each of the automatic valve members I09 downwardly to its lowermost position thereby causing each automatic valve member I09 to open the inlet port H1 and close the corresponding exhaust port I21 for the upper end of the cylinder and at the same time to open the exhaust port I31 of the lower end of the corresponding cylin-' der and close the inlet port I35 for the lower end of the operating cylinder. Compressed air thereupon flows into the end of each operating cylinder and moves the operating piston 53 downwardly to open position. i

1 The three blast valves 13 are each opened simultaneously with the opening Valve mechanism 59 so that a blast of compressed air flows through the hollow insulators 2| to the arc extinguishing structures 23 to quickly extinguish the current arcs drawn as the movable contact members 3| separate from the stationary contacts 29.

Each movable contact member 3| is moved downwardly to open'position by its operating piston 53. The arc is extinguished by the blast of compressed air in the chamber of the arc extinguishing structure before the-movable contact member moves out of the arc extinguishing structure so that the circuit is completely interrupted by this time. Each movable contact member 3| is moved out of the arc extinguishin structure 23 and downwardly for a considerable distance into the corresponding supporting insulator 2| after arc extinction, thus introducing a relatively long safe disconnecting gap in the circuit. By the time the circuit breaker reaches open position, the air blast valves have been returned to closed position, and the solenoid I59 of the opening valve is deenergized and the opening valve returned to closed position, thereby shutting off the opening air.

When the closing valve mechanism 6| is operated to open position, compressed air flows from the tank 5| through the closing air manifold pipe I39, insulators I1, pipes I36, and inlet ports I to the lower ends of the three operating cylinders 55. The compressed air in the pipes I36 immediately pushes the three automatic valve members I09 to their upper end positions. When each automatic valve member is thus actuated to its upper position, it opens the inlet port I35 to the lower end of the operating cylinder 55, and closes the corresponding exhaust port I31, and at the same time opens the exhaust port I21 for the upper end of the operating cylinder and closes the inlet port II1 for the upper end of the operating cylinder. Opening of the exhaust ports I21 causes air above the operating pistons to be exhausted to atmosphere. The flow of compressed air to the lower ends of the three operating cylinders through the inlet ports I35 causes the operating pistons 53 to be moved upwardly to the closed position shown in Fig. 3, thereby moving the contact members 3| to closed position in engagement with their corresponding stationary contacts 29. When the breaker reaches closed position, the solenoid I of the closing valve mechanism 5| is deenergized, and the closing valve mechanism is returned to closed position,

thereby shutting off the closing air. The automatic valves I09 are thereupon returned to neutral position by the springs I53.

A modification of the automatic valve mechanism is shown in Fig. 5. In accordance with this modification of the invention, the automatic valve device is so arranged that a greater actuating force is applied tothe movable valve element by the opening air than by the closing air so that an opening operation of the circuit breaker will always take preference over a closing op .eration in case of conflicting control impulses. Referring to Fig. 5. the automatic valve device I03 is of substantially the same construction as the automatic valve device I03 of the original em bodiment of the invention except that the vertical cylindrical passage in the upper valve housing section I05 and the upper piston element I 41' of the pneumatically operated valve member I09 are of larger diameter than the lower piston element I41. The remaining structure of the automatic valve device is identical to that of the original embodiment. Since the upper piston element I41 is of larger diameter than the lower piston element I41, the flow of compressed air in the pipe 9 for opening the breaker will exert a greater force on the valve member I09 than the force exerted by the flow of closing compressed air in the pipe I36. Consequently, the automatic valve member I09 will always be moved to its lowermost position if compressed air is admitted to the pipes H9 and I36 simultaneously. Under these conditions the valve member I09 moves to its lowermost position, maintaining the inlet port 135' for the lower end of the cylinder closed and thereby preventing the flow of compressed air to the lower end of the operating cylinder. Thus, an opening operation will always take precedence over a closing operation in the event of conflicting control impulses.

While the invention has been disclosed in accordance with the provisions of the Patent Statutes, it is to be understood that various changes in the structural details and arrangement of parts thereof may be made without departing from some of the essential features of the invention. It is desired, therefore, that the language of the appended claims be given the broadest reasonable inte pretation permissible in the light of the prior art.

We claim as our invention:

1. A gas blast circuit breaker comprising a circuit interrupting element, a hollow member of insulating material supporting said interrupting element, a stationary contact associated with said interrupting element, a cooperating movable contact engageable with said stationary contact, said circuit interrupting element having an arc extinguishing chamber and means for confining the are within said chamber and preventing the arc from entering the passage of the hollow insulating member, compressed gas operatingmeans for said movable contact operable to move said c'ontact out of the interrupting element after arc extinction and into the chamber of said hollow supporting member to insert a safe enclosed disconnecting gap in series with the interrupting element capable of withstanding high voltages, and means for causing the arc to be extinguished in the interrupting chamber before the moving contact moves into the chamber of the hollow insulator.

A gas blast circuit breaker comprising an arc extinguishing structure having an arc extinguishing chamber and means for directing blast gas to the are. a hollow porcelain insulator supporting said are extinguishing structure, a stationary contact associated with said are extinguishing structure, said arc extinguishing structure having means for confining the arc within said chamber and preventing the are from entering the interior passage of said hollow insulator, a cooperating movable contact, and operating means for moving said movable contact I to open and closed position, said operating means being operable to move said movable contact out of said arc extinguishing structure and into the space enclosed by said insulator after extinction of the arc to provide a safe disconnecting gap in the circuit capable of withstanding high voltages. I

3. A gas blast circuit breaker comprising an -arc extinguishing structure having an are extinguishing chamber, a hollow porcelain insulator supporting said are extinguishing structure and having a disconnect chamber communicating with said arc extinguishing chamber, a stationary contact associated with said are extinguishing structure, said are extinguishing structure having means for confining the arc within said chamber and preventing the are from entering the interior passage of said hollow insulator, a cooperating disconnect contact movable in said chambers into and out of engagement with said stationary contact, operating means for moving said disconnect contact, said operating means being operable to move said disconnect contact out of said are extinguishing structure and a substantial distance into the disconnect chamber of said insulator after arc extinction to provide a safe disconnecting gap in the circuit, and means for supplying a blast of arc extinguishing gas through the chamber of said insulator to the arc.

4. A gas blast circuit breaker comprising an arc extinguishing structure having an are extinguishing chamber, a bailie provided with an orifice through which the arc plays and having means for directing blast gas substantially radially toward the arc and out through said orifice, a hollow porcelain insulator supporting said are extinguishing structure, a stationary contact in said arc extinguishing structure adjacent said orifice, said arc extinguishing structure having means for confining the are within said chamber and preventing the are from entering the interior passage of said hollow insulator, a cooperating movable contact engageable with said stationary contact, operating means for moving said movable contact to open and to closed position, said operating means being operable to move said contact out of said are extinguishing structure ar'ter extinction of the arc and a substantial distance into said supporting insulator to provide a safe disconnecting gap in the circuit capable of withstanding high voltages, and means for supplying a blast of arc extinguishing gas through said insulator to said arc extinguishing structure.

5. A compressed gas circuit breaker comprising an arc extinguishing structure having an arc extinguishing chamber, a hollow supporting insulator supporting said are extinguishing structure, a stationary contact associated with said are extinguishing structure, said are extinguishing structure having means for confining the are within said chamber and preventing the arc from entering the interior passage of said hollow insulator, a cooperating movable contact engageable with said stationary Contact, compressed gas operating means for moving said movable contact to open and closed position comprising an operating cylinder and a piston in said cylinder mechanically connected to said movable contact, said operating means being operable to move said contact out of said are extinguishing structure aster arc extinction and a substantial distance into said supporting insulator to provide a safe disconnecting gap in the circuit, and means ior supplying a blast of compressed gas through said hollow insulator to said are extinguishing structure to extinguish the are.

6. A circuit breaker comprising a movable contact member, compressed gas operating means for moving said contact member to open and-to closed position comprising a cylinder, a reciprocally movable piston in said cylinder con nected to said contact member, means for supplying compressed gas to said cylinder to move said piston in one direction to close the breaker and to move said piston in the opposite direction to open the breaker, an automatic valve device associated with said cylinder comprising a single movable valve element operated directly by the operating compressed gas to automatically dump gas from said cylinder in front of the moving piston for both directions of movement of said piston.

7. A circuit breaker having a movable contact member, compressed gas operating means for moving said contact member to open and to closed position comprising a cylinder, a piston reciprocally movable in said cylinder and con-- nected to said contact member, means for supplying compressed gas to said cylinder to move said piston in one direction to close the breaker and in the opposite direction to open the breaker, a valve device associated with said cylinder having a gas inlet passage for admitting compressed gas to one end of said cylinder and having an exhaust port for exhausting gas from said one end of the cylinder, a valve element operated directly by the flow of compressed gas to said inlet passage to close said exhaust port, said valve element also being operated by the flow of compressed gas to the other end of said operating cylinder to close said inlet passage and open the exhaust port.

8. A circuit breaker having a movable contact member, compressed air operating means for moving said contact member to open and to closed position comprising a cylinder, a reciprocally movable piston in said cylinder connected to said contact member, an automatic valve device associated with said cylinder having an inlet port and a corresponding exhaust port communicating with one end of said cylinder and a second inlet port and corresponding exhaust port communicating with the opposite end of said cylinder, valve means pneumatically operated by compressed air in either of said inlet ports to close the corresponding exhaust port and open the exhaust port for the opposite end of said cylinder, and means for supplying compressed air through said inlet ports to said cylinder to operate said piston.

9. A circuit breaker having a movable contact member, compressed gas operating means for moving said contact member to open and to closed position comprising a cylinder and a reciprocally movable piston in said cylinder connected to said contact member, means forsupplying compressed gas to the opposite ends of said cylinder to open or to close the breaker, a separate exhaust port for each end of said cylinder,-and a single valve member operated directly by the flow of operating compressed gas to either end of said cylinder to close the corresponding exhaust port and open the exhaust port of the opposite end of said cylinder.

10. A circuit breaker having a movable contact member, compressed gas operating means for moving said contact member to open and to closed position comprising a cylinder, a double acting piston in said cylinder connected to said contact member, means including a pair of compressed gas supply lines and a pair of inlet ports for supplying compressed gas to the opposite ends of said cylinder to open or close the breaker, a separate exhaust port for each end of said cylinder, and a single movable valve member pneumatically operated by the flow of operating compressed gas to either end of said cylinder to open the exhaust port of the opposite end of said cylinder and close the inlet port of said opposite end of the cylinder.

11. In a circuit breaker having a movable contact member, compressed gas operating means for moving said contact member to open and to closed position comprising a cylinder and a piston reciprocally movable in said cylinder connected to said contact member, means for supplying compressed gas to the ends of said cylinder to actuate said contact member to open or to closed position, an automatic valve device associated with said cylinder having an inlet port and a corresponding exhaust port communicating with one end of said cylinder, a second inlet port and corresponding exhaust port communicating with the other end of said cylinder, and movable valve means operated by compressed gas in either of said inlet ports to automatically close the corresponding exhaust port and open the exhaust port of the opposite end of the cylinder and close the inlet port of said opposite end of the cylinder.

12. A circuit breaker having a movable contact member, compressed gas operating means for moving said contact member to open and to closed position comprising a cylinder and a piston reciprocally movable in said cylinder connected to said contact member, means for supplying compressed gas to one end of said cylinder to actuate said contact member to open position and to the other end of said cylinder to actuate said contact member to closed position, an automatic valve device having an inlet port and a corresponding exhaust port communicating with said one end of the cylinder and a second inlet port and corresponding exhaust port communicating with the other end of said cylinder, and a single movable valve member operable by operating compressed gas in either of said inlet ports to automatically close the corresponding exhaust port and open the exhaust port of the opposite end of the cylinder and close the inlet port of said opposite end of the cylinder, said valve member having a pressure reactive surface subject to the closing gas and a pressure reactive surface of larger area subject to the opening gas to cause an opening operation of the breaker to always take preference over a closing operation.

13. A circuit breaker having a movable contact member, compressed gas operating means for moving said contact member to open and to closed position comprising a cylinder and a piston reciprocally movable in said cylinder connected to said contact member, means for supplying compressed gas to one end of said cylinder to actuate said contact member to open position and to the other end of said cylinder to actuate said contact member to closed position, an automatic valve device having an inlet port and a corresponding exhaust port communicating with said one end of the cylinder and a second inlet port and corresponding exhaust port communicating with the other end ,of said cylinder, and a single movable valve member operable by operating compressed gas in either of said inlet ports to automatically close the corresponding exhaust port and open the exhaust port of the opposite end of the cylinder and close the inlet port of said opposite end of the cylinder, said valve member being subjected to a greater operating force by the circuit breaker opening gas than by the circuit' breaker closing gas to thereby cause an opening operation of the breaker to always take preference over a closing operation in case of confiicting operating impulses.

14. A circuit breaker having a movable contact member, compressed air operating means for moving said contact member to open and to closed position comprising a cylinder, a piston reciprocally movable in said cylinder and connected to said contact member, means including a pair of compressed air supply lines for supplying compressed air to the opposite ends of opening 01 the breaker in one of said lines and a valve for controlling closing of the breaker in the other of said lines, and an automatic valve device associated with said cylinder having an inlet port and an exhaust port for each end of said cylinder and a single movable valve member pneumatically actuated by the opening air to automatically open the exhaust port of the closing end of the cylinder and close the inlet supply port for the closing end of the cylinder and pneumatically actuated by the closing air to automatically open the exhaust port oi the opening end of said cylinder and close the inlet supply port of the opening end of said cylinder.

15. A circuit breaker having a movable contact member, compressed air operating means for moving said contact member to open and to closed position comprising a cylinder, a piston reciprocally movable in said cylinder and connected to said contact member, means including a pair of compressed air supply lines for supplying compressed air to the opposite ends 0. said cylinder, a valve for controlling opening of the breaker in one of said lines and a valve for controlling closing of the breaker in the other of said lines, and an automatic valve device associated with said cylind r having an inlet port and an exhaust port for each end of said cylinder and a single movable valve member pneumatically actuated by the opening air to automatically open the exhaust port of the closing end of the cylinder and close the inlet supply port for the closing end of the cylinder and pneumatically actuated by the closing air to automatically open the exhaust port of the opening end of said cylinder and close the inlet supply port of the opening end of said cylinder, said valve member being subjected to a greater actuating force by the opening com pressed air than by the closing compressed air to thereby cause an opening operation to always take preference over a closing operation in case of conflicting operating impulses.

16. A gas blast circuit breaker comprising an arc extinguishing structure having an arc extinguishing chamber, a hollow supporting insulator supporting said structure, a stationary contact associated with said are extinguishing structure, a cooperating movable contact extending within the passage of said insulator and movable into said are extinguishing structure to closed position in engagement with said sta tionary contact, compressed gas operating means for moving said contact member to open and to closed position, said contact member when moved to open position being moved out of said are extingumhing structure after arc extinction and a considerable distance into the passage of said supporting insulator to provide a safe disconnecting gap in the circuit, said operating means comprising a cylinder, a piston in said cylinder connected to said contact member, means for supplying compressed gas to opposite ends of said cylinder to move said piston in one direction to close the breaker and in the oppo site direction to open the breaker, an automatic valve device associated with said cylinder comprising a single movable valve element 1 cylinder, a valve for controlling operated by the operating compressed gas to automatically exhaust gas from said cylinder in front of the moving piston for both directions of movement of said piston to thereby facilitate high speed closing-opening operation and high speed reclosing operation of the movable contact member.

17. A gas blast circuit breaker comprising a plurality of hollow supporting insulators, a single one piece metal casting mounted on said insulators having an operating cylinder formed therein, and having a gas blast conduit formed integral therewith communicating at one end with the passage of one of said supporting insulators, a hollow insulator mounted on said casting having a passage communicating with the other end of said blast conduit, an arc extinguishing structure mounted on the top of said hollow insulator, a stationary contact associated with said are extinguishing structure, a cooperating movable contact member extending within the passage of said hollow insulator and engageable with said stationary contact, and an operating piston in said cylinder connected to said movable contact.

18. A high voltage compressed gas circuit breaker comprising a plurality of mechanically independent pole units each having means including contact means for interrupting the circuit and for providing an isolating gap in the circuit capable of withstanding high voltages, compressed gas operating means comprising a separate operating cylinder for each of said pole units, a reciprocally movable piston in each cylinder connected to a corresponding one of said contact means,. a compressed gas system including a source of compressed gas, a single opening valve mechanism common to all of said cylinders operable to control the flow of compressed gas to one end of all of said cylinders for opening the breaker, and a single closing valve mechanism common to all of said cylinders operable to control. the flow of compressed gas to the other end of all of said cylinders for closing the breaker.

3.9. A compressed air circuit breaker comprising a plurality of mechanically independent pole units each having a movable contact member, compressed air operating means comprising a separate operating cylinder for each of said pole units, a reciprocally movable piston in each cylinder connected to a corresponding one of said contact members, a compressed air system including a source of compressed air, a single opening valve mechanism common to all of said cylinders operable to control the flow of compressed air to one end of all of said cylinders for opening the breaker, and a single closing valve mechanism common to all of said cylinders operable to control the flow of compressed air to the other end of all of said cylinders for closing the breaker, and an automatic valve device associated with each of said cylinders operated by the opening and closing air to automatically dump air from said cylinder ahead of the moving piston to facilitate high speed opening and reclosing operation of the breaker.

20. A compressed air circuit breaker comprising a plurality of mechanically independent pole units each having a movable contact member, compressed air operating means comprising a separate operating cylinder for each of said pole units, a reciprocally movable piston in each cylinder connected to a corresponding one of said contact members, a compressed air system including a source oi compressed air, a single opening valve mechanism common to all of said cylinders operable to control the flow of compressed airto one end of all 01' said cylinders for opening the breaker, and a single closing valve mechanism common to all of said cylinders operable to control the flow of compressed air to the other end of all of said cylinders for closing the breaker, a separate blast valve for each pole unit for controlling the flow of arc extinguishing blast air, and means interlocking at least one of said blast valves with said single opening valve mechanism to prevent opening of said opening valve mechanism if said blast valve fails to open.

LEON R. LUDWIG.

BENJAMIN P. BAKER.

JAMES M. CUMMING. 

